Broiler



06f. 6, 1964 B. B. HANsoN ETAL BROILER 2 Sheets-Sheet l Filed Aug. 3,1960 Ill 23 \22 31.510/2g\310,)/A A A/ y JQ' 25 16 m I Q E Inlfm1/anfora-F ernard/fansom ff emo/5 0 Oct. 6, 1964 B. E. HANsoN ETALBROILER Filed Aug. 5, 1960 2 Sheets-snee?. 2

United States Patent O 3,151,616 BROILER Bernard B. Hanson, EugeneStoligrosz, and llames E. Davis, all of Hamilton, (Ehio, assignors toWhirlpool Corporation, a corporation of Delaware Filed Aug. 3, 1966,Ser. No. 47,188 2 Claims. (Cl. 126-41) This invention relates to abroiler and particularly to an oven for cooking food that can also beused to broil food.

ln broiling with gas with an ordinary burner the llame length and heatintensity is sufcient to burn substantially all of the combustible gasesor smoke evolved from the broiling food so that substantially noobnoxious smoke and gases pass from the broiler into the room. Thiscondition, however, is not present with a broiler using the porous powerburner which is now popular. 1n the porous power burner fuel gas and airmixture is forced under pressure through the burner which is usually inthe form of a porous plate and is burned on one surface of the porousburner. Here the llame length is so short that the combustible gasesgiven off from the food being broiled are not burned suiicientlycompletely so that smoke and irritating gases tend to pass from thebroiler into the room.

One of the features of this invention is to provide a broiler using aporousl power burner and including means for promoting substantiallycomplete combustion of the combustible gases given oft from the materialbeing broiled.

Other features and advantages of the invention will be apparent from theillustrated embodiment thereof shown in the accompanying drawings. Ofthe drawings:

FIGURE l is a vertical sectional view through a household oven andbroiler combination embodying the invention.

FIGURE 2 is a sectional view taken substantially along line 2 2 ofFIGURE l.

FIGURE 3 is the electrical Wiring diagram for the illustratedembodiment.

The oven illustrated in the above drawings is generally similar to thatdisclosed in the copending Stoligrosz application Serial No. 836,229,filed August 26, 1959, now Patent No. 3,063,441, and assigned to thesame assignee. This oven includes the baking space 1li formed in acharnber 11, a front access door 12 having an air veut 13 at the bottomthereof for incoming air, an air circulating fan 14- at the upper rearof the oven located at the top of a vertical due 15 having an entrance16 to the fan at the top of the ilue and an exit 17 adjacent the bottomof the flue and the bottom of the oven. The fan 14 is operated by anelectric motor 13 located rearwardly of the flue 15. There is alsoprovided a porous plate burner at the top of the oven space 19 withmeans including a conduit 2i) for supplying a fuel gas and air mixtureto the burner 19. This mixture is supplied by the conduit 2t) to achamber 21 on the surface of the Vplate 19 opposite the burning surface22. In this type of burner the air and gas mixture is forced through theplate 19 under pressure from an electrically operated blower 23 (FIGURE3).

Porous burner plate 19 is located at the top of the oven. Immediatelybeneath the burner is adapted to be located a movable rack 24 forsupporting meat 25 or the like during a broiling operation.

Also located in the top of the oven adjacent the surface 22 of theburner plate 19 is a llame detection switch 26 that includes a bimetal.There is also provided a spark plug 27 adapted to be used in conjunctionwith spaced contacts 28 and 29 located adjacent the peripheral edge 313of the plate 19 for igniting the gas emerging through the plate 19. Theflame detection switch 26 is protected ice from accidental injury bymeans of a protective plate 31 located beneath the switch 26 and mountedon depending brackets 31a.

Extending around the peripheral edge 3l? of the porous burner plate 19is a vent 32 that follows this edge and that extends generally upwardly.The vent is formed from sheet metal 33 and has an upwardly extendingportion 34 at one side thereof. From this upwardly extending portionthere is located an upwardly and outwardly sloped vent ilue 35 thatempties into the ambient atmosphere through decorative louvers 36.

Positioned in the flue 35 is a plate valve 37 mounted for oscillationabout a transverse axis 38. This valve is normally closed as shown inFIGURE l during the baking operation and is provided with a downwardlyextending operating arm 39.

In order to open the valve 37 when desired there is provided a bimetalstrip 4i) that curls toward the arm 39 when heated and away from the arm39 when cool. This bimetal strip 46 is anchored at one end to anelectrical insulating fitting 41 and is provided at its upper movableend with a contact pad 42 for contacting the operating arm 39 of thevalve 37. Wrapped around the bimetal 4i) for heating the same is anelectric resistance heater wire 43.

The wiring diagram shown in FIGURE 3 in addition to the oven air blower14, gas and air supply blower 23, fan detection switch 26 and ignitionspark contacts 28 and 29 previously described also includes a timermotor 44, timer contacts 45 and 46, an oven selector switch 47 includingmovable contacts 48, 49, 50 and 51 and ixed contacts 52 and 53, oventhermostat 54, air pressure switch 55, time delay switch 56, time delayswitch heater 57, safety resistor 58, gas valve solenoid 59, transformer66 for the ignition spari; contacts 28 and 29 and relay coil 61 andrelay contacts 62.

The electric power to the electrical circuit is supplied by leads 63 and64. Between these leads is connected the timer motor 44 by line 65.Contacts 45 and 46 are in line 66 which extends from lead 63 to theswitch 47. This line 66 is connected to contacts 52 and 53.

Extending from power lead 64 is line 67 with the fuel gas and air blower23 being connected between this line 67 and contact 48 by means of line68. The heater 43 for the bimetal 46 is connected by means of line 69between line 67 and movable contact 49. The blower 18 for the oven airis connected by means of line 76 between movable contact 50 and line 67.A line 71 which extends between movable contact 51 and line 67 containsin series the thermostat 54, air pressure switch 55, time delay switchheater 57, relay coil 61 and flame detection switch 26. The time delayswitch 56 is in line 72 extending between line 71 and a line 73 whichcontains the safety resistor 58 and the gas valve solenoid 59 and whichis connected to line 67. Between the resistor 58Y and solenoid 59 isconnected one end of a line 74 whose other end is connected to one ofthe fixed contacts 75 of the relay contacts 62. The other xed contact 76is connected by way of a line 77 to one side of the transformer 60 whoseother side is connected by means of a line 78 to the line 67.

During operation of the oven for baking the timer contacts 45 and 46 areclosed and the contacts 48 and 52 are closed and the contacts 5G and 53and 51 and 53 are closed. This serves to energize the blower 23 whichsupplies air land gas mixture to the burner plate 19 and the oven airblower motor 18 which circulates air through the oven by way of the ue15 and the openings 17 and 16.

When broiling of meat or the like is to be done the timer contacts 45and 46 are closed and contacts 48, 49

and 52 are closed. Similarly, contacts 51 and 53 are Y closed. Thisclosing of the contacts serves to activate 'f The quick shut-oi orsafety Y a'safety feature. Y

' is shut off power to the ignition circuit willvbe interrupted.

the fuel gas and air mixture blower 23 and the heater 43 for thebimetal40. The heater 43 causesthe bimetal 40 to bend toward the operating arm39 of the valve 37 with the result that the contact pad 42 engages thearm 39 and turns the valve 37 to the open position indicated by thebroken lines in FIGURE 1. This open the vent 32 to the ambientatmosphere through the decorative louvers 36 so that smoke and othercombustible` gases from the meat Y25 being broiled tend to ow toward andthrough the vent 32. As` the vent 32 is closely adjacent the peripheraledge of the burner 19 these combustible gases are subjected to heat fromthe burner plate 19. In order to intensify the heat there is providedmeans adjacent the entrance 79 to the vent 32 for concentrating thecombustible gases adjacent the burner 19 prior to the gases enteringthis entrance. In the embodiment shown this means includes a flange 80located at the outer extremity of the entrance 79 and extendingtowardthe burner plate 19. As a result of this construction the combustiblegases from the food being broiled are subjected to relatively hightemperature so that they are ignited and burned. The resulting gasesthen ow upwardly in the vent 32 -and out the flue 35 and aresubstantially clear of smoke. Y

As can be seen, therefore, the electrical system for the illustratedembodiment provides for closing of the valve 37 'during baking so thatthe oven operates in a normal manner. However, during broiling the valve37 is opened Vso that the smoke and other combustible gases from the byclosing the-contacts 50 and 53. The air pressure setV lup by this blower18 closes the air pressure switch 55 bodiment shown in the accompanyingdrawings, it is ourV intention that the invention be not limited by anyof the details of description, unless otherwise specified, butl ratherbe construed broadly within its spirit and scope as set out in theaccompanying claims.

The embodiments of the invention in which an exe elusive property orprivilege Vis claimed are defined as follows:

1. A broiler, comprising: means forming archamber; a porous powerburnertherein having a substantially continuous porous surface exposedto said chamber; means for supplyingra lfuel gas and air mixture underpressure to said burner for ilow therethrough and Combustionon saidsurface; means adjacent said surface for supporting which results involtage being applied across the ignition Y circuitry. One branch of thecurrent set up by this voltage passes'through the safety switch heater58, the relay coil 61 and the ame detection switch 26 which is normallyclosed when cold. Another branch of the current set up by this voltagepasses through the switch 56 and to the relay contacts 62. A lead 74from the relay contact 75 bypasses the resistor 58 and energizes the-gasvalve solenoid 59. A lead 77 from the other relay contact 76 energizesthe primary of the step-up-transformer 60. The voltage induced in thesecondary winding of this transformer is large enough to force a sparkacross the gap between the ignition spark contacts 28 and 29;

Vthus causing burner ignition.

AfterV normal ignition the-llame detection switch 26 which isY adjacentthe burner 19V opens because of heat received from this burner. Theopening of this switch Y deenergizes the relay coil 61 and the Vsafetyswitch heater V57'. Thisopens the relays contacts 75 and 76 inV relaythe ignition sparking. f

resistor 58 is supplied as If'electrical power `to the apparatus Thiswill immediately shut off the entire` system. The

supplied the main burner` valve solenoid could not operate. If itwerepermitted to Yreopen 4raw 'gas' would ow in large quantities-intothe oven and could not be food for broiling; means forming a vent fromsaid chamber having an open entrance portion that is located in itsentirety extending around said porous burner and adjacent said surfaceor the burning of combustible gases from said broiling foodsubstantially completely at said entrance portion from heat suppliedfromsaid combustion on said surface, said ventY varying in verticalheight and having a highest portion; Van upwardly and outwardly slopedvent Vflue substantiallyat said highest portion; a normallyclosed valvein said ue; and means for opening said valve during said broiling.

2. A broiler, comprising:v means forming a chamber; a porous powerburner therein having a substantially continuous porous surface exposedto said chamber; means for supplying a fuel gas and air Ymixture underpressure to said burner for flow therethrough and combustion on saidsurface; means adjacent said surface for supporting food for broiling;means forming a vent from said chamber having an open entrance portionthat is located in its entirety extending around said porous burner andadjacent said surface for Athe burning of'combustible gases from saidbroiling food substantially,V completely at said entrance portion fromheat suppliedfrom said combustion on said surface, said vent varying invertical height 1 Vand having a highest portion; an upwardly andoutwardly sloped vent ue substantially at said highest portion; anormally closed valve insaid ue; heat actuated means for opening saidvalve during'said broiling; an electric heater in thermal conductingrelationship with said heat 1 actuated means; and means for electricallyenergizing said heater to open said yvalve during said broiling.

References Cited in the tile of Ythis patent i UNTED STATESVPATENTS1,223,308 Bone et al. Apr. 17, 1917 1,515,234 Woodson Nov. .11, 192411,932,170 -gBibb Oct. 24,1933Y 2,102,482V Parker- Dec. 14, 19372,164,078 'Y Parker 'Iune 27, 1939 2,164,079 Parker June 27, 19392,219,787 Parker Oct. 29, 1940 2,323,821 Lindemannfet al. July 6, 19432,862,095 Scofield Nov. 25,Y 1958 `2,908,267 Hess f v f Ocala, 1959

1. A BROILER, COMPRISING: MEANS FORMING A CHAMBER; A POROUS POWER BURNERTHEREIN HAVING A SUBSTANTIALLY CONTINUOUS POROUS SURFACE EXPOSED TO SAIDCHAMBER; MEANS FOR SUPPLYING A FUEL GAS AND AIR MIXTURE UNDER PRESSURETO SAID BURNER FOR FLOW THERETHROUGH AND COMBUSTION ON SAID SURFACE;MEANS ADJACENT SAID SURFACE FOR SUPPORTING FOOD FOR BROILING; MEANSFORMING A VENT FROM SAID CHAMBER HAVING AN OPEN ENTRANCE PORTION THAT ISLOCATED IN ITS ENTIRETY EXTENDING AROUND SAID POROUS BURNER AND ADJACENTSAID SURFACE FOR THE BURNING OF COMBUSTIBLE GASES FROM SAID BROILINGFOOD SUBSTANTIALLY COMPLETELY AT SAID ENTRANCE PORTION FROM HEATSUPPLIED FROM SAID COMBUSTION ON SAID SURFACE, SAID VENT VARYING INVERTICAL HEIGHT AND HAVING A HIGHEST PORTION; AN UPWARDLY AND OUTWARDLYSLOPED VENT FLUE SUBSTANTIALLY AT SAID HIGHEST PORTION; A NORMALLYCLOSED VALVE IN SAID FLUE; AND MEANS FOR OPENING SAID VALVE DURING SAIDBROILING.